Great links for math teachers, students, and parents:
Math TV - a great site of videos where teachers and students demonstrate how to solve many different mathematical problems.

Cut-The-Knot - an interactive math website full of games, puzzles, and demonstrations.

Coolmath Games - exactly like the title of the site, a great collection of cool math games for people of all ages.

Study Island - a standards-based learning site which is a great classroom supplement and standardized test preparation tool (PSSA, PSAT, SAT, etc.).

TeacherTube - a great site for viewing educational videos and presentations.

BHASD Webpage - the main website for Brandywine Heights Area School District.

Graphing a line using Slope-Intercept Form (y=mx+b), check out this site.

Here is the Stem-and-Leaf Plots page

Check out this cool game: Algebra vs. The Cockroaches

Here is the link to the Proportions and Similarity Activity

Here are the links to the Logarithms Introduction #1 and Logarithms Introduction #2